While Donald Trump may not have the support of some in the Republican Party, it won't hurt his fundraising efforts, thanks to his "huge" broad-based support across the country, campaign finance chairman Steve Mnuchin said Friday.
The Trump campaign announced this week it raised about $51 million in June along with the Republican National Committee.
"We had no fundraising effort whatsoever, and in five weeks with very broad support, you see how we're doing," Mnuchin said in an interview with CNBC's "Power Lunch."
"I think we'll continue at that pace, and as we get out of the convention, I think it will increase significantly."
He said he was particularly pleased with the campaign's digital effort, noting that there were several occasions when about $3 million was raised in a single day.
"I think we're picking up a lot of Bernie Sanders supporters and seeing a lot of support online."
Trump met with Congressional Republicans on Thursday and had a fairly smooth meeting with House members. However, things got tense in his Senate meeting when Sen. Jeff Flake, R-Arizona, told Trump he couldn't support him yet because of his criticism of Sen. John McCain's time as a prisoner of war during the Vietnam War.
Former presidents George W. Bush and George H.W. Bush have said they are abstaining from the election, and former presidential candidate Mitt Romney has said he could not support Trump.
—CNBC's John Harwood contributed to this report.